[FFmpeg-devel] [PATCH]Use pushfl/popfl in cpuid.c

Måns Rullgård mans
Mon Nov 24 11:23:32 CET 2008

Reimar D?ffinger wrote:
> On Mon, Nov 24, 2008 at 03:32:21AM +0100, Michael Niedermayer wrote:
>> On Sun, Nov 23, 2008 at 08:42:11PM +0100, Reimar D?ffinger wrote:
>> > On Sun, Nov 23, 2008 at 07:34:49PM +0100, Michael Niedermayer wrote:
>> > > so it seems we are back to .byte 0x9C
>> >
>> > Hm, I'd be in favour of disabling the check on x86_64 and then going for
>> > pushfl, or do you dislike that for some reason?
>> IMHO if there is a cpuid flag on x86_64 (and i think there is but i
>> didnt check) then it seems correct to check it ..
>> but of course the argument, that all x86_64 cpus will likely support
>> cpuid is pretty good as well, so i surely have no strong oppinion on
>> this
> Well, I just checked, the x86_64 specification does not actually require
> it it seems.

Has there been, or is there likely ever to be, an implementation without

> How about
> #ifdef ARCH_X86_64
> #define PUSHF "pushfq\n\t"
> #define POPF  "popfq\n\t"
> #else
> #define PUSHF "pushfl\n\t"
> #define POPF  "popfl\n\t"
> #endif
> ?

Just make sure you test it on both.

M?ns Rullg?rd
mans at mansr.com

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